1. Field of the Invention
The invention relates generally to the field of rotating wing aircraft (e.g. helicopter) position and orientation determination using radar. More specifically, the invention relates to devices and methods applied to enhance safety of helicopter landing under brownout (sand and/or dust) or whiteout (snow and/or fog) conditions created by the aircraft's main-rotor down-wash, under which near-ground flight is particularly perilous due to the sudden loss of visual cues on which the pilot depends.
2. Background Art
United States Defense Advanced Research Projects Agency (DARPA) Broad Agency Announcement No. BAA 06-45 requests solicitations for proposals to deal with affordable solutions to the problem of helicopter landing in brownout as well as other degraded visual environments (DVEs) such as whiteouts caused by snow and/or fog. Solutions are needed for the brownout phenomenon, which causes deadly accidents during helicopter landing and take-off operations in arid desert terrain. Intense, blinding dust clouds, which may be stirred up by the aircraft's main-rotor down-wash during near-ground flight can cause helicopter pilots to suddenly lose all visual cues. This creates significant flight safety risks from aircraft and ground obstacle collisions, rollover due to sloped and uneven terrain, etc.
What is needed is a sensor/visualization-display system that will effectively provide an affordable, landing capability in brownout/DVE conditions where the visibility is temporarily as low as zero with zero landing-zone infrastructure and limited knowledge of the terrain comprising the landing area. The invention may also be permanently deployed as an integral safety feature for landing areas experiencing frequent degradation of visibility such as offshore oil rigs (e.g. fog), desert installations (e.g. sand and dust) and Arctic/Antarctic installations (e.g. snow).